// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#include "google/protobuf/compiler/csharp/csharp_reflection_class.h"

#include <sstream>

#include "google/protobuf/compiler/code_generator.h"
#include "absl/strings/str_join.h"
#include "google/protobuf/compiler/csharp/csharp_enum.h"
#include "google/protobuf/compiler/csharp/csharp_field_base.h"
#include "google/protobuf/compiler/csharp/csharp_helpers.h"
#include "google/protobuf/compiler/csharp/csharp_message.h"
#include "google/protobuf/compiler/csharp/csharp_options.h"
#include "google/protobuf/compiler/csharp/names.h"
#include "google/protobuf/descriptor.h"
#include "google/protobuf/descriptor.pb.h"
#include "google/protobuf/io/printer.h"

// Must be last.
#include "google/protobuf/port_def.inc"

namespace google
{
  namespace protobuf
  {
    namespace compiler
    {
      namespace csharp
      {

        ReflectionClassGenerator::ReflectionClassGenerator(const FileDescriptor *file,
                                                           const Options *options)
            : SourceGeneratorBase(options),
              file_(file)
        {
          namespace_ = GetFileNamespace(file);
          reflectionClassname_ = GetReflectionClassUnqualifiedName(file);
          extensionClassname_ = GetExtensionClassUnqualifiedName(file);
        }

        ReflectionClassGenerator::~ReflectionClassGenerator()
        {
        }

        void ReflectionClassGenerator::Generate(io::Printer *printer)
        {
          WriteIntroduction(printer);

          // WriteDescriptor(printer);
          // Close the class declaration.
          // printer->Outdent();
          //  printer->Print("}\n");

          if (file_->extension_count() > 0)
          {
            printer->Print(
                "/// <summary>Holder for extension identifiers generated from the top "
                "level of $file_name$</summary>\n"
                "$access_level$ static partial class $class_name$ {\n",
                "access_level", class_access_level(), "class_name", extensionClassname_,
                "file_name", file_->name());
            printer->Indent();
            for (int i = 0; i < file_->extension_count(); i++)
            {
              std::unique_ptr<FieldGeneratorBase> generator(
                  CreateFieldGenerator(file_->extension(i), -1, this->options()));
              generator->GenerateExtensionCode(printer);
            }
            printer->Outdent();
            printer->Print(
                "}\n"
                "\n");
          }

          // write children: Enums
          if (file_->enum_type_count() > 0)
          {
            printer->Print("#region Enums\n");
            for (int i = 0; i < file_->enum_type_count(); i++)
            {
              EnumGenerator enumGenerator(file_->enum_type(i), this->options());
              enumGenerator.Generate(printer);
            }
            printer->Print("#endregion\n");
            printer->Print("\n");
          }

          // write children: Messages
          if (file_->message_type_count() > 0)
          {
            printer->Print("#region Messages\n");
            for (int i = 0; i < file_->message_type_count(); i++)
            {
              MessageGenerator messageGenerator(file_->message_type(i), this->options());
              messageGenerator.Generate(printer);
            }
            printer->Print("#endregion\n");
            printer->Print("\n");
          }

          // TODO: add insertion point for services.

          if (!namespace_.empty())
          {
            printer->Outdent();
            printer->Print("}\n");
          }
          printer->Print("\n");
          printer->Print("#endregion Designer generated code\n");
        }

        void ReflectionClassGenerator::WriteIntroduction(io::Printer *printer)
        {
          printer->Print(
              "// <auto-generated>\n"
              "//     Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
              "//     source: $file_name$\n"
              "// </auto-generated>\n"
              "#pragma warning disable 1591, 0612, 3021, 8981\n"
              "#region Designer generated code\n"
              "\n"
              "using pb = global::Google.Protobuf;\n"
              "using pbc = global::Google.Protobuf.Collections;\n"
              // "using pbr = global::Google.Protobuf.Reflection;\n"
              "using scg = global::System.Collections.Generic;\n",
              "file_name", file_->name());

          if (!namespace_.empty())
          {
            printer->Print("namespace $namespace$ {\n", "namespace", namespace_);
            printer->Indent();
            printer->Print("\n");
          }

          // printer->Print(
          //     "/// <summary>Holder for reflection information generated from $file_name$</summary>\n"
          //     "$access_level$ static partial class $reflection_class_name$ {\n"
          //     "\n",
          //     "file_name", file_->name(),
          //     "access_level", class_access_level(),
          //     "reflection_class_name", reflectionClassname_);
          // printer->Indent();
        }

        void ReflectionClassGenerator::WriteDescriptor(io::Printer *printer)
        {
          printer->Print(
              "#region Descriptor\n"
              "/// <summary>File descriptor for $file_name$</summary>\n"
              "public static pbr::FileDescriptor Descriptor {\n"
              "  get { return descriptor; }\n"
              "}\n"
              "private static pbr::FileDescriptor descriptor;\n"
              "\n"
              "static $reflection_class_name$() {\n",
              "file_name", file_->name(),
              "reflection_class_name", reflectionClassname_);
          printer->Indent();
          printer->Print(
              "byte[] descriptorData = global::System.Convert.FromBase64String(\n");
          printer->Indent();
          printer->Indent();
          printer->Print("string.Concat(\n");
          printer->Indent();

          // TODO: Consider a C#-escaping format here instead of just Base64.
          std::string base64 = FileDescriptorToBase64(file_);
          while (base64.size() > 60)
          {
            printer->Print("\"$base64$\",\n", "base64", base64.substr(0, 60));
            base64 = base64.substr(60);
          }
          printer->Print("\"$base64$\"));\n", "base64", base64);
          printer->Outdent();
          printer->Outdent();
          printer->Outdent();

          // -----------------------------------------------------------------
          // Invoke InternalBuildGeneratedFileFrom() to build the file.
          printer->Print(
              "descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,\n");
          printer->Print("    new pbr::FileDescriptor[] { ");
          for (int i = 0; i < file_->dependency_count(); i++)
          {
            printer->Print(
                "$full_reflection_class_name$.Descriptor, ",
                "full_reflection_class_name",
                GetReflectionClassName(file_->dependency(i)));
          }
          printer->Print("},\n"
                         "    new pbr::GeneratedClrTypeInfo(");
          // Specify all the generated code information, recursively.
          if (file_->enum_type_count() > 0)
          {
            printer->Print("new[] {");
            for (int i = 0; i < file_->enum_type_count(); i++)
            {
              printer->Print("typeof($type_name$), ", "type_name", GetClassName(file_->enum_type(i)));
            }
            printer->Print("}, ");
          }
          else
          {
            printer->Print("null, ");
          }
          if (file_->extension_count() > 0)
          {
            std::vector<std::string> extensions;
            for (int i = 0; i < file_->extension_count(); i++)
            {
              extensions.push_back(GetFullExtensionName(file_->extension(i)));
            }
            printer->Print("new pb::Extension[] { $extensions$ }, ", "extensions", absl::StrJoin(extensions, ", "));
          }
          else
          {
            printer->Print("null, ");
          }
          if (file_->message_type_count() > 0)
          {
            printer->Print("new pbr::GeneratedClrTypeInfo[] {\n");
            printer->Indent();
            printer->Indent();
            printer->Indent();
            for (int i = 0; i < file_->message_type_count(); i++)
            {
              WriteGeneratedCodeInfo(file_->message_type(i), printer, i == file_->message_type_count() - 1);
            }
            printer->Outdent();
            printer->Print("\n}));\n");
            printer->Outdent();
            printer->Outdent();
          }
          else
          {
            printer->Print("null));\n");
          }

          printer->Outdent();
          printer->Print("}\n");
          printer->Print("#endregion\n\n");
        }

        // Write out the generated code for a particular message. This consists of the CLR type, property names
        // corresponding to fields, names corresponding to oneofs, nested enums, and nested types. Each array part
        // can be specified as null if it would be empty, to make the generated code somewhat simpler to read.
        // We write a line break at the end of each generated code info, so that in the final file we'll see all
        // the types, pre-ordered depth first, one per line. The indentation will be slightly unusual,
        // in that it will look like a single array when it's actually constructing a tree, but it'll be easy to
        // read even with multiple levels of nesting.
        // The "last" parameter indicates whether this message descriptor is the last one being printed in this immediate
        // context. It governs whether or not a trailing comma and newline is written after the constructor, effectively
        // just controlling the formatting in the generated code.
        void ReflectionClassGenerator::WriteGeneratedCodeInfo(const Descriptor *descriptor, io::Printer *printer, bool last)
        {
          if (IsMapEntryMessage(descriptor))
          {
            printer->Print("null, ");
            return;
          }
          // Generated message type
          printer->Print("new pbr::GeneratedClrTypeInfo(typeof($type_name$), $type_name$.Parser, ", "type_name", GetClassName(descriptor));

          // Fields
          if (descriptor->field_count() > 0)
          {
            std::vector<std::string> fields;
            fields.reserve(descriptor->field_count());
            for (int i = 0; i < descriptor->field_count(); i++)
            {
              fields.push_back(GetPropertyName(descriptor->field(i)));
            }
            printer->Print("new[]{ \"$fields$\" }, ", "fields", absl::StrJoin(fields, "\", \""));
          }
          else
          {
            printer->Print("null, ");
          }

          // Oneofs
          if (descriptor->oneof_decl_count() > 0)
          {
            std::vector<std::string> oneofs;
            oneofs.reserve(descriptor->oneof_decl_count());
            for (int i = 0; i < descriptor->oneof_decl_count(); i++)
            {
              oneofs.push_back(UnderscoresToCamelCase(descriptor->oneof_decl(i)->name(), true));
            }
            printer->Print("new[]{ \"$oneofs$\" }, ", "oneofs", absl::StrJoin(oneofs, "\", \""));
          }
          else
          {
            printer->Print("null, ");
          }

          // Nested enums
          if (descriptor->enum_type_count() > 0)
          {
            std::vector<std::string> enums;
            enums.reserve(descriptor->enum_type_count());
            for (int i = 0; i < descriptor->enum_type_count(); i++)
            {
              enums.push_back(GetClassName(descriptor->enum_type(i)));
            }
            printer->Print("new[]{ typeof($enums$) }, ", "enums", absl::StrJoin(enums, "), typeof("));
          }
          else
          {
            printer->Print("null, ");
          }

          // Extensions
          if (descriptor->extension_count() > 0)
          {
            std::vector<std::string> extensions;
            for (int i = 0; i < descriptor->extension_count(); i++)
            {
              extensions.push_back(GetFullExtensionName(descriptor->extension(i)));
            }
            printer->Print("new pb::Extension[] { $extensions$ }, ", "extensions", absl::StrJoin(extensions, ", "));
          }
          else
          {
            printer->Print("null, ");
          }

          // Nested types
          if (descriptor->nested_type_count() > 0)
          {
            // Need to specify array type explicitly here, as all elements may be null.
            printer->Print("new pbr::GeneratedClrTypeInfo[] { ");
            for (int i = 0; i < descriptor->nested_type_count(); i++)
            {
              WriteGeneratedCodeInfo(descriptor->nested_type(i), printer, i == descriptor->nested_type_count() - 1);
            }
            printer->Print("}");
          }
          else
          {
            printer->Print("null");
          }
          printer->Print(last ? ")" : "),\n");
        }

      } // namespace csharp
    }   // namespace compiler
  }     // namespace protobuf
} // namespace google

#include "google/protobuf/port_undef.inc"
